Various properties associated with the world around us are constantly measured by sensing devices. Numerous properties of weather are continuously measured, and weather is predicted based on these observations. Measurements of ocean waves and currents may be used to warn ships of impending problems. The movement over time of a glacier or volcano can be measured by sensors. However, it can be difficult to provide power to these sensing devices, especially when the sensing device is not near a power source. Even when power is readily available, running electrical wires to a sensing device may negatively affect the integrity of the measurement. Further, when powering sensing devices using a battery, features may be severely limited to prolong the life of the battery. For example, capturing real-time video may be impractical using a battery powered sensing device.